Login Form was working and isn't any longer

Site URL: https://waldrondesigns.com/client-login

My software provider offers a code for our clients to login. I applied it to my page and it worked well for several months. Today, a client emailed me saying that it was not working. I tried copying and pasting the code again, thinking that there may have been an update to the code, with no avail.

My code is below- perhaps someone sees an issue with the code? Everything seems fine to me... 

                                                                <div style="background:#fff;border:2px solid #ccc;border-radius:4px;margin:0 auto;width:90%;max-width:400px;">
                                                                    <div style="background:#ccc;color:#fff;font-size:1em;padding:.5em;text-align:center;">CLIENT LOGIN</div>
                                                                        <iframe src="https://client.contractorforeman.net/client_external_login.php" style="border:0px;height:190px;margin-top:1em;width:100%;" frameborder="0" scrolling="no"></iframe>
                                                                    </div>
                                                            </div>

I see fine here.